BOL, Croatia – No.1 seed Tamara Zidansek survived a stern examination from Stefanie Voegele to win, 3-6, 6-2, 6-3 and progress through to the quarterfinals of the Croatia Bol Open.

Neither player was comfortable on serve in an opening set that saw 15 break points created and six taken. Four went the way of the Swiss WTA World No.97, who tiptoed into the ascendancy.

Although the second began in a similar fashion, with the players exchanging breaks, Zidansek found some rhythm on her delivery to run out a comfortable winner.

The decider followed the same pattern, with the Slovenian cutting clear in the middle part of the set to establish an advantage that even allowed her to drop a game when serving for the match.

She will face another Swiss player in the last eight in the form of Timea Bacsinszky, who had a rather more comfortable 6-2, 6-4 victory over Japan’s Nao Hibino.

Elsewhere in the top half, Aleksandra Krunic, the No.3 seed for the week, powered to a rapid 6-2, 6-1 success in under an hour against Ana Bogdan.

There was a shock, however, in the day's final match as Kaja Juvan defeated No.5 seed Astra Sharma, 6-1, 6-0 in just 47 minutes.

At the opposite side of the draw, there were victories for the highest ranked players. No.2 seed Sara Sorribes Tormo won through in 81 minutes against Varvara Flink, 6-3, 6-3 and Jil Teichmann was a quick winner against Ysaline Bonaventure, 6-2, 6-2.

Anna Karolina Schmiedlova had a more complicated passage through, the No.4 seed coming from a set down to overcome Anna-Lena Friedsam, 4-6, 6-0, 7-6(6) in a thrilling encounter.

Laura Siegemund endured similar difficulties against Terez Mrdeza before winning, 3-6, 7-5(5), 6-1.